Table 1 Inclusion and exclusion criteria

Adults aged 18–65 years

History of epilepsy or seizures

Diagnosis of a mild intellectual developmental disability

History of acquired brain injury

History of 1 or more incidents of aggression in the last month

Having metal in the brain/skull, e.g. splinters, fragments, or clips

Consent to participate in the trial by the individual or their substitute decision-maker

Having a cochlear implant

Having an implanted neuro-stimulator (e.g. direct brain stimulation, epidural/subdural stimulation, vagal nerve stimulation)

History of brain surgery or procedure

History of severe adverse reaction to tDCS

Having a cardiac pacemaker or intracardiac lines

Current alcohol or drug misuse

Having a sensitive scalp